At one time I had a post with boatloads of photos here on how to build solar filters...but the website died...

You can go to Baader's website, where there's a page with DIY instructions.

My versions were a bit different, in that you could switch out the material you used.

I built a double set of filters for a pair of 10x50 binoculars, a 3" reflector, and a 4 1/2" reflector, all using the same basic (but scaled) construction method -- and each filter had both the Baader AstroSolar and Thousand Oaks material that could be switched.

Baader filters give a very bright silvery-white image. Thousand Oaks gives a much more mellow golden color. I'm partial to the Thousand Oaks because it's easier on my eyes.

__________________
"If a tree is cut down in the rainforest, and is used to make paper to print a book, and the book is really bad, and there's nobody that will read it, do you still hear a sucking sound?"
Charlie in Dayton, A.AsC.